The invention relates to an interconnection network between semiconductor structures, comprising a waveguide for the transfer of a signal between the semiconductor structures, a transmitter to receive the signal of a first semiconductor structure and to couple the signal into the waveguide, and a receiver to receive the signal from the waveguide and forward it to a second semiconductor structure. Such interconnection networks are used on integrated circuits in order to transfer any of a data signal, a command signals or a clock signal between different semiconductor structures. These semiconductor structures can, as an example, comprise storage cells or computing structures.
A conventional interconnection network between different semiconductor structures on integrated circuits is manufactured by use of resistive conductors. For this purpose an appropriate sub-region of the surface of the semiconductor is metalized with aluminum, gold or copper. Electric signals can be coupled to one end of said metalized areas and are received at the other end. However what is disadvantageous here is that such an interconnect has an electric capacity and a resistance, which must be recharged each time a signal is transmitted. Since the current available for recharging this capacity is limited by the electrical resistance of the circuitry, signal delays arise in the integrated circuit. On an integrated circuit featuring a structure size of 65 nm, this delay is a factor of 5 larger than the gate delays of the arithmetic unit or the storage device.
In order to reduce these delays it is known to introduce additional transistors as signal repeaters and amplifiers. For this purpose however additional circuit elements are required on the integrated circuit, which increase the susceptibility to defects, the current consumption and the manufacturing costs of the integrated circuit.
It is known to introduce optical interconnections between semiconductor structures to solve this problem. In this case the signal processing is possible at the velocity of light and thus independently of charge carrier drift velocities and capacitances. However the level of effort required is several times greater. The electrical signals generated on the semiconductor structures must be converted into optical signals first. For this purpose special opto-electronic circuit elements are required, which by reason of the indirect band gap of a silicon die cannot be manufactured in silicon technology of known art. At the endpoint of the optical waveguide this optical signal must then be converted with the same level of effort back into an electrical signal. Furthermore, efficient optical elements require geometrical dimensions of the same order as the wavelength of the light used. However, CMOS structures commercially used at the present time already have structure sizes of 90 nm or less. No semiconductor elements are available as transmitter diodes for radiation at a 90 nm wavelength.
The object of the invention is therefore to transfer the electrical signals of a first semiconductor structure to a second semiconductor structure without having to undertake a conversion of the electrical signal into an optical signal and without the delay induced by the capacity and the resistance of a conventional interconnecting network.